A retractor system's frame typically includes a rail clamp, a cross bar and two universal joints which are permanently mounted to the cross bar. In addition, two lateral arms, an extension arm and two universal joints may be added. Many surgical cases require only the use of two lateral arms. However, when the surgeon wishes to enclose the frame he secures the extension arm to the lateral arms with two universal joints. The enclosing of the frame thus requires five additional components to be added to the cross bar which is very versatile but time consuming to erect.
It is therefore an object of the present invention to provide the versatility while reducing the five components to one.